04-11-2017 07:41 AM
Several VDX 6740s in a fabric running 6.0.2b. We observe TX errors on multiple interfaces connected to endpoint devices (mainly Lenovo servers with some F5 appliances). The rate is quite low (4/8 errors per 20-30 seconds interval) but it's still there.
No other errors are reported (0 discards and 0 RX errors) and not all servers are affected. Also, no issues with ISL ports.
I tried to spot a pattern, but in vain: we see it with 1GB/10GB (all copper) interfaces, being a member or not of a Port-channel, under some load or no load at all. Replacing the cable doesn't seem to help.
Any hints would be greatly appreciated.
04-12-2017 05:14 AM
Apparently, as per the Release Notes (Limitations and Restrictions):
VDX 6740/6740T/6740T-1G/6940 platforms do not support IP fragmentation.
MTU errors are reported in “show interface” as “Errors” under the “Transmit Statistics”.